1. Field of the Invention
The present invention relates to sensors and alarm systems for use in monitoring a circuit for breaks or shorts.
2. Description of the Prior Art
Alarm systems utilizing two separate pairs of sensor lines for monitoring a circuit for breaks or shorts are known in the art. Such systems use one pair of sensor lines having a series of normally closed switches disposed in line and a second pair of sensor lines having a number of normally open switches disposed in parallel across the line.
The normally closed series of switches are used to monitor a normally closed zone of the circuit, and the normally open switches are used to monitor a normally open zone of the circuit. A test switch must be connected in parallel across the normally open switches and must be manually activated to test the circuit. Continuous monitoring is thus not possible.